GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/h264_mp4toannexb_bsf.c Lines: 107 153 69.9 %
Date: 2019-11-20 04:07:19 Branches: 67 116 57.8 %

Line Branch Exec Source
1
/*
2
 * H.264 MP4 to Annex B byte stream format filter
3
 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21
22
#include <string.h>
23
24
#include "libavutil/intreadwrite.h"
25
#include "libavutil/mem.h"
26
27
#include "avcodec.h"
28
#include "bsf.h"
29
#include "h264.h"
30
31
typedef struct H264BSFContext {
32
    int32_t  sps_offset;
33
    int32_t  pps_offset;
34
    uint8_t  length_size;
35
    uint8_t  new_idr;
36
    uint8_t  idr_sps_seen;
37
    uint8_t  idr_pps_seen;
38
    int      extradata_parsed;
39
} H264BSFContext;
40
41
1740
static int alloc_and_copy(AVPacket *out,
42
                          const uint8_t *sps_pps, uint32_t sps_pps_size,
43
                          const uint8_t *in, uint32_t in_size, int ps)
44
{
45
1740
    uint32_t offset         = out->size;
46

1740
    uint8_t start_code_size = offset == 0 || ps ? 4 : 3;
47
    int err;
48
49
1740
    err = av_grow_packet(out, sps_pps_size + in_size + start_code_size);
50
1740
    if (err < 0)
51
        return err;
52
53
1740
    if (sps_pps)
54
14
        memcpy(out->data + offset, sps_pps, sps_pps_size);
55
1740
    memcpy(out->data + sps_pps_size + start_code_size + offset, in, in_size);
56
1740
    if (start_code_size == 4) {
57
412
        AV_WB32(out->data + offset + sps_pps_size, 1);
58
    } else {
59
1328
        (out->data + offset + sps_pps_size)[0] =
60
1328
        (out->data + offset + sps_pps_size)[1] = 0;
61
1328
        (out->data + offset + sps_pps_size)[2] = 1;
62
    }
63
64
1740
    return 0;
65
}
66
67
5
static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
68
{
69
5
    H264BSFContext *s = ctx->priv_data;
70
    uint16_t unit_size;
71
5
    uint64_t total_size                 = 0;
72
5
    uint8_t *out                        = NULL, unit_nb, sps_done = 0,
73
5
             sps_seen                   = 0, pps_seen = 0;
74
5
    const uint8_t *extradata            = ctx->par_in->extradata + 4;
75
    static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
76
5
    int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
77
78
5
    s->sps_offset = s->pps_offset = -1;
79
80
    /* retrieve sps and pps unit(s) */
81
5
    unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
82
5
    if (!unit_nb) {
83
        goto pps;
84
    } else {
85
5
        s->sps_offset = 0;
86
5
        sps_seen = 1;
87
    }
88
89
15
    while (unit_nb--) {
90
        int err;
91
92
10
        unit_size   = AV_RB16(extradata);
93
10
        total_size += unit_size + 4;
94
10
        if (total_size > INT_MAX - padding) {
95
            av_log(ctx, AV_LOG_ERROR,
96
                   "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
97
            av_free(out);
98
            return AVERROR(EINVAL);
99
        }
100
10
        if (extradata + 2 + unit_size > ctx->par_in->extradata + ctx->par_in->extradata_size) {
101
            av_log(ctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
102
                   "corrupted stream or invalid MP4/AVCC bitstream\n");
103
            av_free(out);
104
            return AVERROR(EINVAL);
105
        }
106
10
        if ((err = av_reallocp(&out, total_size + padding)) < 0)
107
            return err;
108
10
        memcpy(out + total_size - unit_size - 4, nalu_header, 4);
109
10
        memcpy(out + total_size - unit_size, extradata + 2, unit_size);
110
10
        extradata += 2 + unit_size;
111
10
pps:
112

10
        if (!unit_nb && !sps_done++) {
113
5
            unit_nb = *extradata++; /* number of pps unit(s) */
114
5
            if (unit_nb) {
115
5
                s->pps_offset = total_size;
116
5
                pps_seen = 1;
117
            }
118
        }
119
    }
120
121
5
    if (out)
122
5
        memset(out + total_size, 0, padding);
123
124
5
    if (!sps_seen)
125
        av_log(ctx, AV_LOG_WARNING,
126
               "Warning: SPS NALU missing or invalid. "
127
               "The resulting stream may not play.\n");
128
129
5
    if (!pps_seen)
130
        av_log(ctx, AV_LOG_WARNING,
131
               "Warning: PPS NALU missing or invalid. "
132
               "The resulting stream may not play.\n");
133
134
5
    av_freep(&ctx->par_out->extradata);
135
5
    ctx->par_out->extradata      = out;
136
5
    ctx->par_out->extradata_size = total_size;
137
138
5
    return length_size;
139
}
140
141
5
static int h264_mp4toannexb_init(AVBSFContext *ctx)
142
{
143
5
    H264BSFContext *s = ctx->priv_data;
144
5
    int extra_size = ctx->par_in->extradata_size;
145
    int ret;
146
147
    /* retrieve sps and pps NAL units from extradata */
148

5
    if (!extra_size                                               ||
149

5
        (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
150
5
        (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
151
        av_log(ctx, AV_LOG_VERBOSE,
152
               "The input looks like it is Annex B already\n");
153
5
    } else if (extra_size >= 6) {
154
5
        ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
155
5
        if (ret < 0)
156
            return ret;
157
158
5
        s->length_size      = ret;
159
5
        s->new_idr          = 1;
160
5
        s->idr_sps_seen     = 0;
161
5
        s->idr_pps_seen     = 0;
162
5
        s->extradata_parsed = 1;
163
    } else {
164
        av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
165
        return AVERROR_INVALIDDATA;
166
    }
167
168
5
    return 0;
169
}
170
171
530
static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
172
{
173
530
    H264BSFContext *s = ctx->priv_data;
174
175
    AVPacket *in;
176
    uint8_t unit_type;
177
    int32_t nal_size;
178
530
    uint32_t cumul_size    = 0;
179
    const uint8_t *buf;
180
    const uint8_t *buf_end;
181
    int            buf_size;
182
530
    int ret = 0, i;
183
184
530
    ret = ff_bsf_get_packet(ctx, &in);
185
530
    if (ret < 0)
186
132
        return ret;
187
188
    /* nothing to filter */
189
398
    if (!s->extradata_parsed) {
190
        av_packet_move_ref(out, in);
191
        av_packet_free(&in);
192
        return 0;
193
    }
194
195
398
    buf      = in->data;
196
398
    buf_size = in->size;
197
398
    buf_end  = in->data + in->size;
198
199
    do {
200
1741
        ret= AVERROR(EINVAL);
201
1741
        if (buf + s->length_size > buf_end)
202
            goto fail;
203
204
8705
        for (nal_size = 0, i = 0; i<s->length_size; i++)
205
6964
            nal_size = (nal_size << 8) | buf[i];
206
207
1741
        buf += s->length_size;
208
1741
        unit_type = *buf & 0x1f;
209
210

1741
        if (nal_size > buf_end - buf || nal_size < 0)
211
1
            goto fail;
212
213
1740
        if (unit_type == H264_NAL_SPS)
214
            s->idr_sps_seen = s->new_idr = 1;
215
1740
        else if (unit_type == H264_NAL_PPS) {
216
            s->idr_pps_seen = s->new_idr = 1;
217
            /* if SPS has not been seen yet, prepend the AVCC one to PPS */
218
            if (!s->idr_sps_seen) {
219
                if (s->sps_offset == -1)
220
                    av_log(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
221
                else {
222
                    if ((ret = alloc_and_copy(out,
223
                                         ctx->par_out->extradata + s->sps_offset,
224
                                         s->pps_offset != -1 ? s->pps_offset : ctx->par_out->extradata_size - s->sps_offset,
225
                                         buf, nal_size, 1)) < 0)
226
                        goto fail;
227
                    s->idr_sps_seen = 1;
228
                    goto next_nal;
229
                }
230
            }
231
        }
232
233
        /* if this is a new IDR picture following an IDR picture, reset the idr flag.
234
         * Just check first_mb_in_slice to be 0 as this is the simplest solution.
235
         * This could be checking idr_pic_id instead, but would complexify the parsing. */
236

1740
        if (!s->new_idr && unit_type == H264_NAL_IDR_SLICE && (buf[1] & 0x80))
237
            s->new_idr = 1;
238
239
        /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
240


1740
        if (s->new_idr && unit_type == H264_NAL_IDR_SLICE && !s->idr_sps_seen && !s->idr_pps_seen) {
241
14
            if ((ret=alloc_and_copy(out,
242
14
                               ctx->par_out->extradata, ctx->par_out->extradata_size,
243
                               buf, nal_size, 1)) < 0)
244
                goto fail;
245
14
            s->new_idr = 0;
246
        /* if only SPS has been seen, also insert PPS */
247


1726
        } else if (s->new_idr && unit_type == H264_NAL_IDR_SLICE && s->idr_sps_seen && !s->idr_pps_seen) {
248
            if (s->pps_offset == -1) {
249
                av_log(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
250
                if ((ret = alloc_and_copy(out, NULL, 0, buf, nal_size, 0)) < 0)
251
                    goto fail;
252
            } else if ((ret = alloc_and_copy(out,
253
                                        ctx->par_out->extradata + s->pps_offset, ctx->par_out->extradata_size - s->pps_offset,
254
                                        buf, nal_size, 1)) < 0)
255
                goto fail;
256
        } else {
257

1726
            if ((ret=alloc_and_copy(out, NULL, 0, buf, nal_size, unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS)) < 0)
258
                goto fail;
259

1726
            if (!s->new_idr && unit_type == H264_NAL_SLICE) {
260
12
                s->new_idr = 1;
261
12
                s->idr_sps_seen = 0;
262
12
                s->idr_pps_seen = 0;
263
            }
264
        }
265
266
1714
next_nal:
267
1740
        buf        += nal_size;
268
1740
        cumul_size += nal_size + s->length_size;
269
1740
    } while (cumul_size < buf_size);
270
271
397
    ret = av_packet_copy_props(out, in);
272
397
    if (ret < 0)
273
        goto fail;
274
275
397
fail:
276
398
    if (ret < 0)
277
1
        av_packet_unref(out);
278
398
    av_packet_free(&in);
279
280
398
    return ret;
281
}
282
283
static void h264_mp4toannexb_flush(AVBSFContext *ctx)
284
{
285
    H264BSFContext *s = ctx->priv_data;
286
287
    s->idr_sps_seen = 0;
288
    s->idr_pps_seen = 0;
289
    s->new_idr      = s->extradata_parsed;
290
}
291
292
static const enum AVCodecID codec_ids[] = {
293
    AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
294
};
295
296
const AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
297
    .name           = "h264_mp4toannexb",
298
    .priv_data_size = sizeof(H264BSFContext),
299
    .init           = h264_mp4toannexb_init,
300
    .filter         = h264_mp4toannexb_filter,
301
    .flush          = h264_mp4toannexb_flush,
302
    .codec_ids      = codec_ids,
303
};